Conventionally, medical image diagnosis apparatuses configured to generate a medical image of an examined subject by using radiation are known, including X-ray Computed Tomography (CT) apparatuses, Positron Emission Tomography (PET) apparatuses, Single Photon Emission Computed Tomography (SPECT) apparatuses, and gamma cameras, among others. Such medical image diagnosis apparatuses include a radiation detector configured to detect radiation such as X-rays or γ-rays.
The radiation detector includes a scintillator array configured to emit light (scintillation light) in response to radiation becoming incidence thereto; and a Photodiode Array (PDA) configured to output electrical signals in accordance with the scintillation light. The scintillator array and the PDA function in units of a plurality of detecting elements arranged in a channel direction and a slice direction. A plurality of scintillator arrays and a plurality of PDAs are installed in a radiation detector in the form of detector packages, each of which is a unit that can be replaced when a failure occurs.
Each of the scintillator arrays has partition walls that are formed in a grid formation in a planar view and is divided into units corresponding to a plurality of detecting elements by the partition walls. For example, the partition walls are formed by using a material obtained by sandwiching an aluminum evaporated layer between white polyethylene terephthalate (PET) sheets or reflective material resin such as a white adhesive agent including resin and white particles. To form the partition walls with scintillator crystals by using the reflective material resin, generally speaking, the following steps are performed: forming grooves on the scintillator crystals, impregnating the grooves with the reflective material resin and hardening the reflective material resin, and grinding the rear surface.